Electric condenser



M y 30, 193 K. G. COUTLEE 2,160,6

ELECTRIC CONDENSER Filed Sept. 2, 1936 F/G. F/GZ F/G.4

INVENTOR K.G.COUTLEE BY A TTOPNE V Patented May 30, 1939 UNITED STATESPATENT OFFICE ELECTRIC CONDENSER Application September 2, 1936, SerialNo. 99,020

1 Claim.

This invention relates to electric condensers and more particularly toan improved electrical condenser which is substantially moisture-proofand to a method of manufacturing a substantially moisture-proofcondenser.

An object of this invention is to manufacture economically amoisture-proof condenser which is insulated from the apparatus to whichit is affixed and is of good appearance.

A more particular object of this invention is to protect the housing andsupport the leads of an electric condenserwith a common dielectricmaterial.

Ordinarily the leads of a condenser unit are subjected to considerablehandling in use. For this reason the leads of a condenser are preferablyreinforced. In many uses, too, a condenser housing which isinsulatedfrom the apparatus to which it is attached is also desired.

In accordance with this invention, a condenser unit having leadselectrically connected thereto is completely surrounded by a dielectricmaterial which coalesces with a support for the leads whereby asubstantially moisture-proof container is provided for the condenser.For example, if a housing is employed, the condenser unit is inserted inthe housing which is open at one end. Leads of the condenser unit passthrough the open end of the housing. After a sealing compound has beenplaced into the top of the housing, the housing is covered with amaterial comprising a dielectric such as cellulose acetate. Thismaterial in addition to other functions reinforces the leads and affordsa substantially moistureproof covering for open end of the housingthrough which the leads pass. Preferably tabs are provided when two ormore units are contained within the housing to insulate and separate theleads of one unit from those of another unit. The housing containing theunit is then dipped in or sprayed with a solution of a dielectric, suchas cellulose acetate in acetone, having a viscosity which insures theformation of a protective coating of a desired thickness on the housing.The solvent of the protective coating dielectric also dissolves orsoftens the dielectric covering. Preferably the material comprising thecovering is the same as the protective coating dielectric. The coveringis softened sufllciently as a result of the dipping or sprayingoperation to form one integral covering over the entire con; denserwhereby moisture is substantially prevent 1 ed from entering thecondenser units.

A more comprehensive understanding of this invention is obtained byreference to the accompanying drawing in which: I

Fig. 1 is a front elevation, partly broken away, of a preferredembodiment of this invention;

Fig. 2 is a side elevation, partly broken away, 5 of the embodimentshown in Fig. 1;

Fig. 3 is an exploded view of the top of the embodiment shown in Fig. 1;

Fig. 4 shows the manner of applying a protective coating by means of aspray gun to the condenser shown in Fig. 1;

Figs. 5 and 6 show respectively a front and side elevation,partly'broken away, of another embodiment of this invention.

In the embodiment of this invention shown in Figs. 1, 2, 3 and 4, twocondenser units 1 and 2 are inserted in a collapsible metal tube 3. Thecondenser units l and 2 are formed by rolling together compactlyalternate strips of conducting foil, such as aluminum foil and adielectric, 20 such as paper. Suitableflexible leads 4 and 5 areconnected to the alternate layers of conducting foil of condenser I,while two conducting leads 6 and l are connected to the alternateconducting layers of condenser 2. Casing 3 is constructed of thin leadof a collapsible nature. The casin may be oval or round in form beforebeing pressed into the desired shape. If the condenser units I and 2 areinserted in the casing 3 and the casing with the units therein pressedto the desired shape, the units may be impregnated with a wax 8, such aschlorinated naphthalenes. The portion of the terminals protruding abovethe wax 8 is covered with a petrolatum sealing compound 9 which acts asa moisture-proof seal for the units l and 2 and fills the upper portionof the housing 3 above the impregnating compound 8. The terminal strips4, 5, 6 and l are connected respectively to flexible leads ll, l5, l6and II by means of solder. The flexible tube condenser heretoforedescribed is preferably constructed in accordance with the methoddisclosed -in detail in the copending application of F. J.

Given Serial No. 93,183, filed July 29, 1936.

After the unit is impregnated and sealed, any of the impregnatingcompound 8 and sealing compound 9 adhering to the surface of thehousing3 is preferably removed by cleaning with a solvent. A cap ll) of aninsulating material, such as cellulose acetate, is then placed over. thepliable metallic container 3. The cap 10 is provided with a hole llthrough which the leads H, l5, l6 and I1 pass and two tabs l2 are formedby bending a portion of cap III to a position which is perpendicular tothe top thereof. The tabs I! are placed over the casing 3 one of thetabs separates the terminal strips 4 and 6, while the other separatesthe terminal strips 5 and I. The cap III which is preferably of theorder of 15 mils in thickness is constructed to fit over the open end ofthecasing 3. The leads I4, I5, I6 and I! are inserted through theopening of a cellulose acetate washer I3. The washer I3 is then placedin contact with the cover III.

The condenser casing 3 with the cap and washer in position is thendipped in or sprayed with a solution of a dielectric material such ascellulose acetate lacquer which, if desired, may contain pigments. Thesolvent for the cellulose acetate may be acetone having suitablequantities of a retarder such as ethyl lactate, butyl lactate ordiacetone alcohol. The viscosity of the solution is such as to insure asufiicient thickness of the protective coating of cellulose acetate onthe container. The period of dipping or spraying is suificient to cementthoroughly the washer I3 to the cap I0 and the cap I0 to the container3. The manner of applying the solution of cellulose acetate by means ofspraying is indicated in Fig. 4. A spray gun I8 emitting the solution ofcellulose acetate is directed over the entire condenser includingcontainer 3, cap Ill and Washer I3 to produce a protective coating I9over the entire outside of the condenser. In addition, the dipping orspraying with cellulose acetate results in the formation of two lugs 20of this material which further serve to insulate the terminal strips 3and 6 and 5 and I from each other. Preferably, the flexible leads I4,I5, I6 and I1 are-insulated by means of textiles which have beenimpregnated in a solution of cellulose acetate. If the condenser isdipped in the cellulose acetate lacquer it is inserted in a. tankcontaining the lacquer to about 4; above the top of the celluloseacetate washer I3. The condenser is then slowly withdrawn from the tankat a uniform and slow rate to prevent the formation of bubbles and toobtain as smooth and uniform a surface as possible, After dipping, thecondenser is dried at a temperature of not more than F. in an atmosphereof air having a relative humidity low enough to prevent condensation ofmoisture on the surface of the lacquer.

Figs. 5 and 6 illustrate another modification of this invention in whichthe cap member as pre-' viously described is dispensed with. A singlecondenser unit -ZI consisting of alternate layers of conductingqmaterialsuch as aluminum foil separated bypaper or other insulation is encasedin a pliable metallic container 23. Flexible terminals 2 5 and 25 areconnected to the alternate layers.

These terminals 24 and 25, in turn, are connected respectively toflexible leads 34 and 35, This condenser is impregnated with chlorinatednaphthalenes or other impregnating wax 28 and the upper portion of thecontainer 23 is filled with a sealing compound 29. The flexible leads 34and 35 pass through a cellulose acetate washer 33. The

condenser is dipped or sprayed to form a protective'coating 39 in amanner similar to that described for the condenser shown in Figs. 1 to4.

While the described embodiments of this in-. vention are the foil typeof. condenser, the construction and method are equally applicable tostock'condensers such as mica and foil condensers. Although the cap I0and the washer I3 of the condenser illustrated in Figs. 1 to 4 and thewasher 33 of the condenser shown in Figs. 5 and 6 are cellulose acetateand the solution employed to form the protective coating for bothcondensers is cellulose acetate dissolved in acetone, any otherdielectric material may be employed as the cap and washer of thecondenser and the protective coating may comprise a similar or differentdielectric material. For example, the cap I0 and washer I3 of thecondenser shown in Figs. 1 to 4 may comprise cellulose nitrate and acellulose nitrate lacquer may be employed for the protective coating I9.In the practice of covering the condenser, however, a solvent isemployed which dissolves or softens the cover and washer to form acomplete .and substantially moisture-proof and insulating covering forthe entire'condenser. Although a housing is employed for the condensersheretofore described, this invention also contemplates the support ofthe leads and the covering of the unit with the dielectric material formoisture-proofing the condenser without any container other than thatformed by the dielectric material,

While preferred embodiments of this invention have been illustrated anddescribed, various modifications therein may be made without departingfrom the scope of the appended claim.

What is claimed is:

A condenser comprising a condenser unit, leads for electricallyconnecting said unit to electrical apparatus, a collapsible tube housingfor containing said unit, said housing having an opening at one end acellulose acetate cover for the open end of said unit, tabs on saidcover for insulating said leads from each other, a cellulose acetatewasher fixedly attached to cover through which said leads pass and athin iilm of cellulose acetate completely covering said housing, washerand cover.

KENNETH G. COUTLEE.

